This is an interesting one for me. I don't have much time to game these days and I'm really enjoying halo because i am finding it very relaxing going around competing bits whilst not having to think that much (playing on heroic). Having read the discussion on the grapple hook, it's immediately apparent to me that the major reason I'm not having to think is that i beat almost every encounter very easily because of the (almost infinite) 'ammo' of the shock grapple ability. I'm having fun but after a few hours the combat is feeling very repetative due to the strength of this ability/mechanic.
I don't mind it too much as i get a maximum of an hour to play the game a few times a week however from an objective perspective, I can see it detracts from the quality of each encounter as I'm able to clear almost everything with a battle rifle and the grapple ability therefore not experiencing the variety weapons and encounters in a more unique way.
Of course I could force myself to not use the grapple, not use the BR and not use the map for better exploration but those would be of my own design rather than the game (time constraints mean I choose not to though i do accept it's to the detriment of the sandbox on offer).